Pub Date : 2024-10-22Epub Date: 2024-10-04DOI: 10.1021/acs.est.4c04048
Chelsea W Neil, Katherine C Swager, S Michelle Bourret, John P Ortiz, Philip H Stauffer
The detection of noble gas radioisotopes following a suspected underground nuclear explosion is the surest indicator that nuclear detonation has occurred. However, the accurate interpretation and attribution of radioisotopic signatures is only possible with a complete understanding of transport processes occurring between the nuclear cavity and surface. In the far-field, diffusive forces contributing to gas transport are impacted by temperature gradients and subsurface lithology. In the current study, we investigate diffusive transport of xenon (Xe), krypton (Kr), and sulfur hexafluoride (SF6) through intact Bandelier tuff at elevated temperatures using a newly developed high temperature diffusion cell. Diffusion coefficients determined using Finite Element Heat and Mass transfer code simulations and the Parameter ESTimation tool range from 2.6-3.1 × 10-6 m2/s at 20 °C, 3.4-5.1 × 10-6 m2/s at 40 °C, and 4.3-7.0 × 10-6 m2/s at 70 °C. Sorption was found to be an important transport mechanism at ambient temperatures (20 °C). Most critically, our study shows that empirical porosity-based diffusion estimates for these gases through tuff captured neither the magnitude nor trends relative to a nonsorbing sandstone. These new insights highlight the importance of experimental transport investigations and will be used to improve models for subsurface gas propagation relevant to proliferation detection and environmental contamination.
{"title":"Rethinking Porosity-Based Diffusivity Estimates for Sorptive Gas Transport at Variable Temperatures.","authors":"Chelsea W Neil, Katherine C Swager, S Michelle Bourret, John P Ortiz, Philip H Stauffer","doi":"10.1021/acs.est.4c04048","DOIUrl":"10.1021/acs.est.4c04048","url":null,"abstract":"<p><p>The detection of noble gas radioisotopes following a suspected underground nuclear explosion is the surest indicator that nuclear detonation has occurred. However, the accurate interpretation and attribution of radioisotopic signatures is only possible with a complete understanding of transport processes occurring between the nuclear cavity and surface. In the far-field, diffusive forces contributing to gas transport are impacted by temperature gradients and subsurface lithology. In the current study, we investigate diffusive transport of xenon (Xe), krypton (Kr), and sulfur hexafluoride (SF<sub>6</sub>) through intact Bandelier tuff at elevated temperatures using a newly developed high temperature diffusion cell. Diffusion coefficients determined using Finite Element Heat and Mass transfer code simulations and the Parameter ESTimation tool range from 2.6-3.1 × 10<sup>-6</sup> m<sup>2</sup>/s at 20 °C, 3.4-5.1 × 10<sup>-6</sup> m<sup>2</sup>/s at 40 °C, and 4.3-7.0 × 10<sup>-6</sup> m<sup>2</sup>/s at 70 °C. Sorption was found to be an important transport mechanism at ambient temperatures (20 °C). Most critically, our study shows that empirical porosity-based diffusion estimates for these gases through tuff captured neither the magnitude nor trends relative to a nonsorbing sandstone. These new insights highlight the importance of experimental transport investigations and will be used to improve models for subsurface gas propagation relevant to proliferation detection and environmental contamination.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22Epub Date: 2024-09-04DOI: 10.1021/acs.est.4c06638
Qing Yang, Yuanzheng Zhang, Pengyu Xiao, Ruiping Liu, Huijuan Liu, Jiuhui Qu, Jae-Hong Kim, Meng Sun
Producing H2O2 through a selective, two-electron (2e) oxygen reduction reaction (ORR) is challenging, especially when it serves as an advanced oxidation process (AOP) for cost-effective water decontamination. Herein, we attain a 2e-selectivity H2O2 production using a carbon nanotube electrified membrane with ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast, single-pass electrofiltration process. The IBU@CNT-EM can generate H2O2 at a rate of 25.62 mol gCNT-1 h-1 L-1 in the permeate with a residence time of 1.81 s. We demonstrated that an interwoven, hydrophilic-hydrophobic membrane nanostructure offers an excellent air-to-water transport platform for ORR acceleration. The electron transfer number of the ORR for IBU@CNT at neutral pH was confirmed as 2.71, elucidating a near-2e selectivity to H2O2. Density functional theory (DFT) studies validated an exceptional charge distribution of the IBU@CNT for the O2 adsorption. The adsorption energies of the O2 and *OOH intermediates are proportional to the H2O2 selectivity (64.39%), higher than that of the CNT (37.81%). With the simple and durable production of H2O2 by IBU@CNT-EM electrofiltration, the permeate can actuate Fenton oxidation to efficiently decompose emerging pollutants and inactivate bacteria. Our study introduces a new paradigm for developing high-performance H2O2-production membranes for water treatment by reusing environmental functional materials.
{"title":"Selective O<sub>2</sub>-to-H<sub>2</sub>O<sub>2</sub> Electrosynthesis by a High-Performance, Single-Pass Electrofiltration System Using Ibuprofen-Laden CNT Membranes.","authors":"Qing Yang, Yuanzheng Zhang, Pengyu Xiao, Ruiping Liu, Huijuan Liu, Jiuhui Qu, Jae-Hong Kim, Meng Sun","doi":"10.1021/acs.est.4c06638","DOIUrl":"10.1021/acs.est.4c06638","url":null,"abstract":"<p><p>Producing H<sub>2</sub>O<sub>2</sub> through a selective, two-electron (2e) oxygen reduction reaction (ORR) is challenging, especially when it serves as an advanced oxidation process (AOP) for cost-effective water decontamination. Herein, we attain a 2e-selectivity H<sub>2</sub>O<sub>2</sub> production using a carbon nanotube electrified membrane with ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast, single-pass electrofiltration process. The IBU@CNT-EM can generate H<sub>2</sub>O<sub>2</sub> at a rate of 25.62 mol g<sub>CNT</sub><sup>-1</sup> h<sup>-1</sup> L<sup>-1</sup> in the permeate with a residence time of 1.81 s. We demonstrated that an interwoven, hydrophilic-hydrophobic membrane nanostructure offers an excellent air-to-water transport platform for ORR acceleration. The electron transfer number of the ORR for IBU@CNT at neutral pH was confirmed as 2.71, elucidating a near-2e selectivity to H<sub>2</sub>O<sub>2</sub>. Density functional theory (DFT) studies validated an exceptional charge distribution of the IBU@CNT for the O<sub>2</sub> adsorption. The adsorption energies of the O<sub>2</sub> and *OOH intermediates are proportional to the H<sub>2</sub>O<sub>2</sub> selectivity (64.39%), higher than that of the CNT (37.81%). With the simple and durable production of H<sub>2</sub>O<sub>2</sub> by IBU@CNT-EM electrofiltration, the permeate can actuate Fenton oxidation to efficiently decompose emerging pollutants and inactivate bacteria. Our study introduces a new paradigm for developing high-performance H<sub>2</sub>O<sub>2</sub>-production membranes for water treatment by reusing environmental functional materials.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22Epub Date: 2024-09-24DOI: 10.1021/acs.est.4c05620
Jinghua Zhang, Yuxin Ma, Peigen Lin, Minghong Cai
Organophosphate esters (OPEs) have been observed in the remote Arctic Ocean, yet the influence of hydrodynamics and seasonal sea ice variations on the occurrence and transport of waterborne OPEs remains unclear. This study comprehensively examines OPEs in surface seawater of the central Arctic Ocean during the summer of 2020, integrating surface ocean current and sea ice concentration data. The results confirm significant spatiotemporal variations of the OPEs, with the total concentration of seven major OPEs averaging 780 ± 970 pg/L. Chlorinated OPEs, particularly tris(1-chloro-2-propyl) phosphate (TCPP), were dominant. The significant impact of hydrodynamics on the OPE transport is demonstrated by higher OPE concentrations in regions with strong surface currents, especially at the edge of the Beaufort Gyre and the confluence of the Beaufort Gyre and the Transpolar Drift. Furthermore, OPE levels were generally higher in drifting-ice-covered regions compared to ice-free regions, attributed to the volatilization of dissolved OPEs formerly trapped below the sea ice or newly released from melting snow and sea ice. Notably, TCPP decreased by only 19% in the ice-free area, while the more volatile triphenyl phosphate decreased by 63% compared with the partial ice region.
{"title":"Regulation of Ocean Surface Currents and Seasonal Sea Ice Variations on the Occurrence and Transport of Organophosphate Esters in the Central Arctic Ocean.","authors":"Jinghua Zhang, Yuxin Ma, Peigen Lin, Minghong Cai","doi":"10.1021/acs.est.4c05620","DOIUrl":"10.1021/acs.est.4c05620","url":null,"abstract":"<p><p>Organophosphate esters (OPEs) have been observed in the remote Arctic Ocean, yet the influence of hydrodynamics and seasonal sea ice variations on the occurrence and transport of waterborne OPEs remains unclear. This study comprehensively examines OPEs in surface seawater of the central Arctic Ocean during the summer of 2020, integrating surface ocean current and sea ice concentration data. The results confirm significant spatiotemporal variations of the OPEs, with the total concentration of seven major OPEs averaging 780 ± 970 pg/L. Chlorinated OPEs, particularly tris(1-chloro-2-propyl) phosphate (TCPP), were dominant. The significant impact of hydrodynamics on the OPE transport is demonstrated by higher OPE concentrations in regions with strong surface currents, especially at the edge of the Beaufort Gyre and the confluence of the Beaufort Gyre and the Transpolar Drift. Furthermore, OPE levels were generally higher in drifting-ice-covered regions compared to ice-free regions, attributed to the volatilization of dissolved OPEs formerly trapped below the sea ice or newly released from melting snow and sea ice. Notably, TCPP decreased by only 19% in the ice-free area, while the more volatile triphenyl phosphate decreased by 63% compared with the partial ice region.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Resource demand by soil microorganisms critically influences microbial metabolism and then influences ecosystem resilience and multifunctionality. The ecological remediation of abandoned tailings is a topic of broad interest, yet our understanding of microbial metabolic status in restored soils, particularly at the aggregate scale, remains limited. This study investigated microbial resources within soil aggregates from revegetated tailings and applied a vector model of ecoenzymatic stoichiometry to examine how different vegetation patterns (grassland, forest, or bare land control) impact microbial resource limitation. Five-year vegetation restoration significantly elevated carbon (C) and nitrogen (N) concentrations and their stoichiometric ratios in soil aggregates (approximately 2-fold), although these increases were not translated to in the microbial biomass and its stoichiometry. The activities of C- and phosphorus (P)-acquiring extracellular enzymes in these aggregates increased substantially postvegetation, with the most pronounced escalation in macroaggregates (>0.25 mm). The vector model results indicated soil microbial metabolism was colimited by C and P, most acutely in microaggregates (<0.25 mm). This colimitation was exacerbated by monotypic vegetation cover but mitigated under diversified vegetation cover. Soil nutrient stoichiometric ratios in vegetation restoration controlled microbial resource limitation, overshadowing the impact of heavy metals. Our findings underscore that optimizing resource allocation within soil aggregates through strategic revegetation can enhance microbial metabolism in tailings, which advocates for the implementation of diverse vegetation covers as a viable strategy to improve the ecological development of degraded landscapes.
{"title":"Diversified Vegetation Cover Alleviates Microbial Resource Limitations within Soil Aggregates in Tailings.","authors":"Wenliang Ju, Jordi Sardans, Haijian Bing, Jie Wang, Dengke Ma, Yongxing Cui, Chengjiao Duan, Xiankun Li, Qiaohui Fan, Josep Peñuelas, Linchuan Fang","doi":"10.1021/acs.est.4c06081","DOIUrl":"10.1021/acs.est.4c06081","url":null,"abstract":"<p><p>Resource demand by soil microorganisms critically influences microbial metabolism and then influences ecosystem resilience and multifunctionality. The ecological remediation of abandoned tailings is a topic of broad interest, yet our understanding of microbial metabolic status in restored soils, particularly at the aggregate scale, remains limited. This study investigated microbial resources within soil aggregates from revegetated tailings and applied a vector model of ecoenzymatic stoichiometry to examine how different vegetation patterns (grassland, forest, or bare land control) impact microbial resource limitation. Five-year vegetation restoration significantly elevated carbon (C) and nitrogen (N) concentrations and their stoichiometric ratios in soil aggregates (approximately 2-fold), although these increases were not translated to in the microbial biomass and its stoichiometry. The activities of C- and phosphorus (P)-acquiring extracellular enzymes in these aggregates increased substantially postvegetation, with the most pronounced escalation in macroaggregates (>0.25 mm). The vector model results indicated soil microbial metabolism was colimited by C and P, most acutely in microaggregates (<0.25 mm). This colimitation was exacerbated by monotypic vegetation cover but mitigated under diversified vegetation cover. Soil nutrient stoichiometric ratios in vegetation restoration controlled microbial resource limitation, overshadowing the impact of heavy metals. Our findings underscore that optimizing resource allocation within soil aggregates through strategic revegetation can enhance microbial metabolism in tailings, which advocates for the implementation of diverse vegetation covers as a viable strategy to improve the ecological development of degraded landscapes.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Havala O T Pye, Lu Xu, Barron H Henderson, Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Jose L Jimenez, Christine Allen, T Nash Skipper, Hannah S Halliday, Benjamin N Murphy, Emma L D'Ambro, Paul O Wennberg, Bryan K Place, Forwood C Wiser, V Faye McNeill, Eric C Apel, Donald R Blake, Matthew M Coggon, John D Crounse, Jessica B Gilman, Georgios I Gkatzelis, Thomas F Hanisco, L Gregory Huey, Joseph M Katich, Aaron Lamplugh, Jakob Lindaas, Jeff Peischl, Jason M St Clair, Carsten Warneke, Glenn M Wolfe, Caroline Womack
Wildfires are an increasing source of emissions into the air, with health effects modulated by the abundance and toxicity of individual species. In this work, we estimate reactive organic compounds (ROC) in western U.S. wildland forest fire smoke using a combination of observations from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign and predictions from the Community Multiscale Air Quality (CMAQ) model. Standard emission inventory methods capture 40-45% of the estimated ROC mass emitted, with estimates of primary organic aerosol particularly low (5-8×). Downwind, gas-phase species abundances in molar units reflect the production of fragmentation products such as formaldehyde and methanol. Mass-based units emphasize larger compounds, which tend to be unidentified at an individual species level, are less volatile, and are typically not measured in the gas phase. Fire emissions are estimated to total 1250 ± 60 g·C of ROC per kg·C of CO, implying as much carbon is emitted as ROC as is emitted as CO. Particulate ROC has the potential to dominate the cancer and noncancer risk of long-term exposure to inhaled smoke, and better constraining these estimates will require information on the toxicity of particulate ROC from forest fires.
{"title":"Evolution of Reactive Organic Compounds and Their Potential Health Risk in Wildfire Smoke.","authors":"Havala O T Pye, Lu Xu, Barron H Henderson, Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Jose L Jimenez, Christine Allen, T Nash Skipper, Hannah S Halliday, Benjamin N Murphy, Emma L D'Ambro, Paul O Wennberg, Bryan K Place, Forwood C Wiser, V Faye McNeill, Eric C Apel, Donald R Blake, Matthew M Coggon, John D Crounse, Jessica B Gilman, Georgios I Gkatzelis, Thomas F Hanisco, L Gregory Huey, Joseph M Katich, Aaron Lamplugh, Jakob Lindaas, Jeff Peischl, Jason M St Clair, Carsten Warneke, Glenn M Wolfe, Caroline Womack","doi":"10.1021/acs.est.4c06187","DOIUrl":"https://doi.org/10.1021/acs.est.4c06187","url":null,"abstract":"<p><p>Wildfires are an increasing source of emissions into the air, with health effects modulated by the abundance and toxicity of individual species. In this work, we estimate reactive organic compounds (ROC) in western U.S. wildland forest fire smoke using a combination of observations from the 2019 Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign and predictions from the Community Multiscale Air Quality (CMAQ) model. Standard emission inventory methods capture 40-45% of the estimated ROC mass emitted, with estimates of primary organic aerosol particularly low (5-8×). Downwind, gas-phase species abundances in molar units reflect the production of fragmentation products such as formaldehyde and methanol. Mass-based units emphasize larger compounds, which tend to be unidentified at an individual species level, are less volatile, and are typically not measured in the gas phase. Fire emissions are estimated to total 1250 ± 60 g·C of ROC per kg·C of CO, implying as much carbon is emitted as ROC as is emitted as CO. Particulate ROC has the potential to dominate the cancer and noncancer risk of long-term exposure to inhaled smoke, and better constraining these estimates will require information on the toxicity of particulate ROC from forest fires.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22Epub Date: 2024-10-10DOI: 10.1021/acs.est.4c03574
Niloofar Karimian, Mark I Pownceby, Edward D Burton, Martin Wells, Andrew J Frierdich
Goethite often harbors impurities, such as phosphorus (P) and aluminum (Al), which are incorporated into its structure through direct substitution or coprecipitation with nanocrystalline phases. Understanding the processes that drive the release of P and Al from goethite is of paramount importance for the iron ore industry and for managing nutrient and pollutant behavior in the environment. This study investigates the impact of Fe(II)-catalyzed recrystallization on the release of P and Al from goethite. We evaluated the solubility and extractability of P and Al in suspensions of Al- and P-coprecipitated goethite, treated with 57Fe-enriched Fe(II)aq under oxygen-free conditions for 30 days at neutral pH and room temperatures. The addition of Fe(II)aq induced the recrystallization of goethite dominant initial synthetic phases (i.e., low P- and Al-containing phases) and the transformation of higher P- and/or Al-bearing starting material that was actually a mixture of goethite and minor amounts of lepidocrocite and feroxyhyte. Our results reveal that Fe(II)-catalyzed mineral and structural evolution led to the repartitioning of P and, to a lesser extent, Al throughout the crystal structure, mineral surface, and aqueous solution. Following a 30 day reaction with Fe(II)aq, we extracted approximately 80, 68.8, 73.9, and 83.2% of P from P-only, low, medium, and high P + Al goethite, respectively. Additionally, we observed total Al removals of approximately 17, 27, and 25% from low, medium, and high P + Al goethite, respectively. The results demonstrate that treating both P-only and P + Al goethite with Fe(II) at room temperature, followed by a 24 h extraction using 1 M NaOH, significantly enhances the overall extractability of P and Al, including both aqueous and surface-adsorbed fractions, compared to Fe(II)-free controls. These findings advance our understanding of the recrystallization process and impurity substitution in goethite, offering promising avenues for developing new environmentally friendly methods to extract P and other impurities from goethitic iron ores at lower temperatures.
透辉石通常含有磷(P)和铝(Al)等杂质,这些杂质通过直接置换或与纳米晶相共沉淀的方式融入透辉石的结构中。了解促使磷和铝从网纹石中释放出来的过程对于铁矿石行业以及管理环境中的营养物质和污染物行为至关重要。本研究调查了铁(II)催化重结晶对钾和铝从鹅铁矿中释放的影响。我们评估了在无氧条件下,在中性 pH 值和室温条件下,用富含 57Fe 的 Fe(II)aq 处理 30 天后,铝和磷重结晶的鹅绿泥石悬浮液中 P 和 Al 的可溶性和可萃取性。加入 Fe(II)aq 后,鹅绿泥石的主要初始合成相(即含 P 和 Al 较低的相)发生了重结晶,而含 P 和/或 Al 较高的起始材料则发生了转变,这些起始材料实际上是鹅绿泥石与少量鳞片闪锌矿和铁氧体的混合物。我们的研究结果表明,铁(II)催化的矿物和结构演变导致了整个晶体结构、矿物表面和水溶液中 P 的重新分配,其次是 Al 的重新分配。与 Fe(II)aq 反应 30 天后,我们分别从纯 P、低 P、中 P 和高 P + Al 的鹅绿泥石中提取了约 80%、68.8%、73.9% 和 83.2%的 P。此外,我们还观察到,低、中、高 P + Al 磁铁矿的总铝去除率分别约为 17%、27% 和 25%。结果表明,与不含铁(II)的对照组相比,在室温下用铁(II)处理纯磷和磷+铝鹅卵石,然后用 1 M NaOH 进行 24 小时萃取,可显著提高磷和铝的总体萃取率,包括水萃取和表面吸附萃取。这些发现加深了我们对鹅铁矿再结晶过程和杂质置换的理解,为开发新的环境友好型方法在较低温度下从鹅铁矿中萃取磷和其他杂质提供了前景广阔的途径。
{"title":"Fe(II)-Catalyzed Recrystallization Drives Phosphorus and Aluminum Release from Goethite.","authors":"Niloofar Karimian, Mark I Pownceby, Edward D Burton, Martin Wells, Andrew J Frierdich","doi":"10.1021/acs.est.4c03574","DOIUrl":"10.1021/acs.est.4c03574","url":null,"abstract":"<p><p>Goethite often harbors impurities, such as phosphorus (P) and aluminum (Al), which are incorporated into its structure through direct substitution or coprecipitation with nanocrystalline phases. Understanding the processes that drive the release of P and Al from goethite is of paramount importance for the iron ore industry and for managing nutrient and pollutant behavior in the environment. This study investigates the impact of Fe(II)-catalyzed recrystallization on the release of P and Al from goethite. We evaluated the solubility and extractability of P and Al in suspensions of Al- and P-coprecipitated goethite, treated with <sup>57</sup>Fe-enriched Fe(II)<sub>aq</sub> under oxygen-free conditions for 30 days at neutral pH and room temperatures. The addition of Fe(II)<sub>aq</sub> induced the recrystallization of goethite dominant initial synthetic phases (i.e., low P- and Al-containing phases) and the transformation of higher P- and/or Al-bearing starting material that was actually a mixture of goethite and minor amounts of lepidocrocite and feroxyhyte. Our results reveal that Fe(II)-catalyzed mineral and structural evolution led to the repartitioning of P and, to a lesser extent, Al throughout the crystal structure, mineral surface, and aqueous solution. Following a 30 day reaction with Fe(II)<sub>aq</sub>, we extracted approximately 80, 68.8, 73.9, and 83.2% of P from P-only, low, medium, and high P + Al goethite, respectively. Additionally, we observed total Al removals of approximately 17, 27, and 25% from low, medium, and high P + Al goethite, respectively. The results demonstrate that treating both P-only and P + Al goethite with Fe(II) at room temperature, followed by a 24 h extraction using 1 M NaOH, significantly enhances the overall extractability of P and Al, including both aqueous and surface-adsorbed fractions, compared to Fe(II)-free controls. These findings advance our understanding of the recrystallization process and impurity substitution in goethite, offering promising avenues for developing new environmentally friendly methods to extract P and other impurities from goethitic iron ores at lower temperatures.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22Epub Date: 2024-10-07DOI: 10.1021/acs.est.4c04164
Magdalena Klotz, Sarah Schmidt, Helene Wiesinger, David Laner, Zhanyun Wang, Stefanie Hellweg
As our planet grapples with the severe repercussions of plastic pollution, mechanical recycling has been proposed as a potential remedy. However, increasing mechanical recycling may have unintended negative consequences. For example, recycling of PVC flooring containing hazardous plasticizers that were used in the past may lead to continued exposure. Here we propose measures to increase recycling while circumventing adverse health impacts caused by legacy additives. For this, we conduct a dynamic substance flow analysis for Switzerland and the time period from 1950 to 2100, focusing on three plasticizers: di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), and di(2-ethylhexyl) terephthalate (DEHT). We quantify the uncertainty of results, check their plausibility against measured concentrations in samples representative for the Swiss market, and compare them with modeled substance flows in Germany. Based on the cross-checked model, future average concentrations of DEHP in PVC flooring on the Swiss market are expected to be above the legal limit of 0.1 wt % for several decades if increased recycling rates are implemented without additional measures. Phasing out the potentially concerning DiNP, too, and preventing phthalates from entering recycling would lower their average market concentrations to values below 0.1 wt % and enable increasing recycling rates without compromising product safety. Analogous measures could help achieve this goal across other European countries and product groups.
{"title":"Increasing the Recycling of PVC Flooring Requires Phthalate Removal for Ensuring Consumers' Safety: A Cross-Checked Substance Flow Analysis of Plasticizers for Switzerland.","authors":"Magdalena Klotz, Sarah Schmidt, Helene Wiesinger, David Laner, Zhanyun Wang, Stefanie Hellweg","doi":"10.1021/acs.est.4c04164","DOIUrl":"10.1021/acs.est.4c04164","url":null,"abstract":"<p><p>As our planet grapples with the severe repercussions of plastic pollution, mechanical recycling has been proposed as a potential remedy. However, increasing mechanical recycling may have unintended negative consequences. For example, recycling of PVC flooring containing hazardous plasticizers that were used in the past may lead to continued exposure. Here we propose measures to increase recycling while circumventing adverse health impacts caused by legacy additives. For this, we conduct a dynamic substance flow analysis for Switzerland and the time period from 1950 to 2100, focusing on three plasticizers: di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), and di(2-ethylhexyl) terephthalate (DEHT). We quantify the uncertainty of results, check their plausibility against measured concentrations in samples representative for the Swiss market, and compare them with modeled substance flows in Germany. Based on the cross-checked model, future average concentrations of DEHP in PVC flooring on the Swiss market are expected to be above the legal limit of 0.1 wt % for several decades if increased recycling rates are implemented without additional measures. Phasing out the potentially concerning DiNP, too, and preventing phthalates from entering recycling would lower their average market concentrations to values below 0.1 wt % and enable increasing recycling rates without compromising product safety. Analogous measures could help achieve this goal across other European countries and product groups.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Particulate matter (PM) undergoing various aging processes in the atmosphere changes its toxicity. However, the mechanism of toxicity evolution is not fully clarified currently. This study demonstrates that photoaging promotes an increase in the oxidative potential (OP) of atmospheric PM by about 30%, and the increased OP is mainly attributed to the production of secondary organic compounds, while water-soluble metal ions contribute only 11%. The OP of nonextractable matters (NEMs) of atmospheric PM was mostly increased after photoaging, followed by water-soluble matters (WSMs). NEM can produce quinone-like functional groups and secondary persistent free radicals during photoaging, which are most likely to produce reactive oxygen species (ROS). For WSM, the conversion of low-oxidation humic-like substances (HULIS) to high-oxidation HULIS is the main reason for the increase in OP. Quinones, nitrophenols, and N-containing heterocycles are the OP contributors produced during the conversion process. Among them, quinones are the main secondary oxidizing active compounds, while nitro-phenolic compounds and N-containing heterocyclic compounds may play a catalyst-like role, facilitating the production of oxidizing active compounds and ROS in the newly converted high-oxidation HULIS. This study clarifies the secondary OP generation mechanism and provides new insights into the uncertainty of PM toxicity during atmospheric aging.
颗粒物(PM)在大气中经历各种老化过程后,其毒性会发生变化。然而,毒性演变的机制目前尚未完全阐明。本研究表明,光老化会促使大气颗粒物的氧化潜能(OP)增加约 30%,OP 的增加主要归因于二次有机化合物的产生,而水溶性金属离子仅占 11%。光照老化后,大气 PM 中不可提取物(NEMs)的氧化还原性主要增加,其次是水溶性物质(WSMs)。非提取物在光照老化过程中会产生醌类官能团和次级持久性自由基,这些自由基最有可能产生活性氧(ROS)。就 WSM 而言,低氧化腐殖样物质(HULIS)向高氧化腐殖样物质的转化是 OP 增加的主要原因。醌类化合物、硝基苯酚和含 N 杂环是转化过程中产生的 OP 贡献者。其中,醌类化合物是主要的二次氧化活性化合物,而硝基酚类化合物和含 N 杂环化合物可能起到类似催化剂的作用,促进新转化的高氧化 HULIS 中氧化活性化合物和 ROS 的产生。这项研究阐明了二次 OP 生成机制,并为大气老化过程中可吸入颗粒物毒性的不确定性提供了新的见解。
{"title":"Investigation of the Mechanism of Oxidative Potential Increase in Atmospheric Particulate Matter during Photoaging: Important Role of Aromatic Nitrogenous Compounds.","authors":"Qingwen Wang, Qingcai Chen, Hao Lin, Jiale Ding, Tong Sha, Yuemei Han","doi":"10.1021/acs.est.4c03199","DOIUrl":"https://doi.org/10.1021/acs.est.4c03199","url":null,"abstract":"<p><p>Particulate matter (PM) undergoing various aging processes in the atmosphere changes its toxicity. However, the mechanism of toxicity evolution is not fully clarified currently. This study demonstrates that photoaging promotes an increase in the oxidative potential (OP) of atmospheric PM by about 30%, and the increased OP is mainly attributed to the production of secondary organic compounds, while water-soluble metal ions contribute only 11%. The OP of nonextractable matters (NEMs) of atmospheric PM was mostly increased after photoaging, followed by water-soluble matters (WSMs). NEM can produce quinone-like functional groups and secondary persistent free radicals during photoaging, which are most likely to produce reactive oxygen species (ROS). For WSM, the conversion of low-oxidation humic-like substances (HULIS) to high-oxidation HULIS is the main reason for the increase in OP. Quinones, nitrophenols, and N-containing heterocycles are the OP contributors produced during the conversion process. Among them, quinones are the main secondary oxidizing active compounds, while nitro-phenolic compounds and N-containing heterocyclic compounds may play a catalyst-like role, facilitating the production of oxidizing active compounds and ROS in the newly converted high-oxidation HULIS. This study clarifies the secondary OP generation mechanism and provides new insights into the uncertainty of PM toxicity during atmospheric aging.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ziyu Wang, Jiangyan Chen, Jianyu Song, Zixuan Pan, Yanqing Cong, Chunhui Du, Qiangbiao Li, Xuchun Li
Efficient removal of contaminants in complex water matrices under mild conditions is highly desirable but still challenging. In this study, we unraveled the overlooked but crucial role of sulfite radical (SO3·–) in the efficient selective reduction of toxic Cr(VI) under near-neutral conditions. Fast removal of Cr(VI) at around pH 7 in sulfite/UV was found to be attributable to high reactivity of SO3·– toward HCrO4– (∼5.3 × 106 M–1 s–1). Furthermore, SO3·– was fast generated in situ via one-electron oxidation of S(IV) by transient reactive protonated Cr(V) and Cr(IV) intermediates. Therefore, the specific reactivity of SO3·– and its in situ generation together resulted in the surprisingly positive effect of nitrate and the efficient reduction of Cr(VI) in authentic surface water and industrial wastewater. A mathematical model was developed to simulate Cr(VI) removal in the process, and thus quantitatively demonstrated the roles of reactive species, i.e., SO3·– contributed to ∼93% of Cr(VI) reduction in surface water. Overall, this study provides an insight into the pivotal role of SO3·– in Cr(VI) reduction, and underscores its significance in selective reduction and detoxification of contaminants.
{"title":"Insight into the Efficient Selective Reduction of Cr(VI) in Sulfite/UV Process under Near-Neutral Conditions: The Critical Role of In Situ-Generated Sulfite Radical","authors":"Ziyu Wang, Jiangyan Chen, Jianyu Song, Zixuan Pan, Yanqing Cong, Chunhui Du, Qiangbiao Li, Xuchun Li","doi":"10.1021/acs.est.4c07010","DOIUrl":"https://doi.org/10.1021/acs.est.4c07010","url":null,"abstract":"Efficient removal of contaminants in complex water matrices under mild conditions is highly desirable but still challenging. In this study, we unraveled the overlooked but crucial role of sulfite radical (SO<sub>3</sub><sup>·–</sup>) in the efficient selective reduction of toxic Cr(VI) under near-neutral conditions. Fast removal of Cr(VI) at around pH 7 in sulfite/UV was found to be attributable to high reactivity of SO<sub>3</sub><sup>·–</sup> toward HCrO<sub>4</sub><sup>–</sup> (∼5.3 × 10<sup>6</sup> M<sup>–1</sup> s<sup>–1</sup>). Furthermore, SO<sub>3</sub><sup>·–</sup> was fast generated in situ via one-electron oxidation of S(IV) by transient reactive protonated Cr(V) and Cr(IV) intermediates. Therefore, the specific reactivity of SO<sub>3</sub><sup>·–</sup> and its in situ generation together resulted in the surprisingly positive effect of nitrate and the efficient reduction of Cr(VI) in authentic surface water and industrial wastewater. A mathematical model was developed to simulate Cr(VI) removal in the process, and thus quantitatively demonstrated the roles of reactive species, i.e., SO<sub>3</sub><sup>·–</sup> contributed to ∼93% of Cr(VI) reduction in surface water. Overall, this study provides an insight into the pivotal role of SO<sub>3</sub><sup>·–</sup> in Cr(VI) reduction, and underscores its significance in selective reduction and detoxification of contaminants.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":9.028,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22Epub Date: 2024-10-07DOI: 10.1021/acs.est.3c06769
Yu Gan, Clarence Ng, Amgad Elgowainy, Jason Marcinkoski
Recent concerns surrounding climate change and the contribution of fossil fuels to greenhouse gas (GHG) emissions have sparked interest and advancements in renewable energy sources including wind, solar, and hydroelectricity. These energy sources, often referred to as "clean energy", generate no operational onsite GHG emissions. They also offer the potential for clean hydrogen production through water electrolysis, presenting a viable solution to create an environmentally friendly alternative energy carrier with the potential to decarbonize industrial processes reliant on hydrogen. To conduct a full life cycle analysis, it is crucial to account for the embodied emissions associated with renewable and nuclear power generation plants as they can significantly impact the GHG emissions linked to hydrogen production and its derived products. In this work, we conducted a comprehensive analysis of the embodied emissions associated with solar photovoltaic (PV), wind, hydro, and nuclear electricity. We investigated the implications of including plant-embodied emissions in the overall emission estimates of electrolysis hydrogen production and subsequently on the production of synthetic ammonia, methanol, and Fischer-Tropsch (FT) fuels. Results show that average embodied GHG emissions of solar PV, wind, hydro, and nuclear electricity generation in the United States (U.S.) were estimated to be 37, 9.8, 7.2, and 0.3 g CO2 e/kWh, respectively. Life cycle GHG emissions of electrolytic hydrogen produced from solar PV, wind, and hydroelectricity were estimated as 2.1, 0.6, and 0.4 kg of CO2 e/kg of H2, respectively, in contrast to the zero-emissions often used when the embodied emissions in their construction were excluded. Average life cycle emission estimates (CO2 e/kg) of synthetic ammonia, methanol, and FT-fuel from solar PV electricity are increased by 5.5, 16, and 49 times, respectively, compared to the case when embodied emissions are excluded. This change also depends on the local irradiance for solar power, which can result in a further increase of GHG emissions by 35-41% in areas of low irradiance or reduce GHG emissions by 21-25% in areas with higher irradiance.
{"title":"Considering Embodied Greenhouse Emissions of Nuclear and Renewable Power Plants for Electrolytic Hydrogen and Its Use for Synthetic Ammonia, Methanol, Fischer-Tropsch Fuel Production.","authors":"Yu Gan, Clarence Ng, Amgad Elgowainy, Jason Marcinkoski","doi":"10.1021/acs.est.3c06769","DOIUrl":"10.1021/acs.est.3c06769","url":null,"abstract":"<p><p>Recent concerns surrounding climate change and the contribution of fossil fuels to greenhouse gas (GHG) emissions have sparked interest and advancements in renewable energy sources including wind, solar, and hydroelectricity. These energy sources, often referred to as \"clean energy\", generate no operational onsite GHG emissions. They also offer the potential for clean hydrogen production through water electrolysis, presenting a viable solution to create an environmentally friendly alternative energy carrier with the potential to decarbonize industrial processes reliant on hydrogen. To conduct a full life cycle analysis, it is crucial to account for the embodied emissions associated with renewable and nuclear power generation plants as they can significantly impact the GHG emissions linked to hydrogen production and its derived products. In this work, we conducted a comprehensive analysis of the embodied emissions associated with solar photovoltaic (PV), wind, hydro, and nuclear electricity. We investigated the implications of including plant-embodied emissions in the overall emission estimates of electrolysis hydrogen production and subsequently on the production of synthetic ammonia, methanol, and Fischer-Tropsch (FT) fuels. Results show that average embodied GHG emissions of solar PV, wind, hydro, and nuclear electricity generation in the United States (U.S.) were estimated to be 37, 9.8, 7.2, and 0.3 g CO<sub>2</sub> e/kWh, respectively. Life cycle GHG emissions of electrolytic hydrogen produced from solar PV, wind, and hydroelectricity were estimated as 2.1, 0.6, and 0.4 kg of CO<sub>2</sub> e/kg of H<sub>2</sub>, respectively, in contrast to the zero-emissions often used when the embodied emissions in their construction were excluded. Average life cycle emission estimates (CO<sub>2</sub> e/kg) of synthetic ammonia, methanol, and FT-fuel from solar PV electricity are increased by 5.5, 16, and 49 times, respectively, compared to the case when embodied emissions are excluded. This change also depends on the local irradiance for solar power, which can result in a further increase of GHG emissions by 35-41% in areas of low irradiance or reduce GHG emissions by 21-25% in areas with higher irradiance.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}